clark and c



u. A. CLARK AND 0. E. LUWt.

TIRE FORMING MANDREL. APPLICATION FILED MAR. T, 1919,

Patented Sept 2 SH TS-SHEET I.

n. A. CLARK AND 0. E. LOWE.

TIRE FORMING MANDREL.

-AFPLlCATl0N FILED MAR. I. 1919.

Pntgnted Sept. 16, 1919.

2 SHEETS-SHEET 2.

of shape and smoothness of surface .ing on a boring mill. 35

I UNITED STATES PATENT OFFICE.

DON A. CLARK AlTD CLYDE E. LOWE, 0F CLEVELAND, OHIO, A SSIGNORS TO THE CIiYbE E. LOWE CONT-ANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

TIRE-FORMING MANDREL.

. Specification of Letters Patent.

Application filed March 7. 1919. Serial No. 251.2s1.

. To all whom it may concern:

' Be it known that we, Don A. CLARK and C YDE E. Lown, citizens of the United States, residing of .Cuyahoga and State of Ohio, have 1nvented a certain new and useful Improveat Cleveland, in the county inent in Tire-Forming Mandrels, of which .the' followin is a full, clear, and exact description, re erence being had to the accom anying drawings.

s invention relates to mandrels for :use in making neumatic tires and the various parts an adjuncts thereof such as casings, tubes, liners, patches, and the like.

These mandrels vary slightly in cross section according to the use intended and ac- ,cording to the manufacturer, but are alike in having a nearly or wholly complete torus shape. Thus the mandrel for an inner tube is generally of substantially circular cross section but does not form a complete ring owing to the necessity upon the sizeof tire to be made thereon.

These devices were formerly made of cast iron and brought to the necessary exactness by turn- This was extremely expensive and also resulted in a very heavy mandrel, entailing much expense in operation. To overcome these disadvantages We have devised mandrels of sheet metal as described and claimed in our Patent No. 1,273,032, granted July 16, 1918, and in our application Serial No. 242,019, filed June 26. 1918, and No. 272,412 filed Jan. 22, 1919.

The object of the present invention is the strengthening of these sheet metal mandrels the better to resist denting and deformation; and the provision of local reinforcement to the vulnerable points of such mandrels so as to enable equal strength to be obtained with the use of thinner metal, thus enhancing the advantages of cheapness, lightness, and permanence. It is found that the chief deformation of these devices comes from peripheral dent-ing caused 'by droppin the mandrels edgewise upon stone floors an the like hard objects; and the essence of the present invention resides inv the formation of integral inturned stiffening flanges at the vulnerable points.

In the drawings accompanying and forming a part of this specification we have shown certain embodiments of our said in= vention as applied -to difi'erent forms and constructions of mandrel although it will be understood that these drawings are illustrative only and'are not intended to limit us to the particular forms and embodiments therein delineated. In these drawings Figure 1 is a plan view of a flanged or key hole core as employed in the manufacture. of pneumatic tire casing; Figs. 2, 3, 4, and 5 are cross sectional views showing different details of construction of such key hole cores, all however embodying our said invention; Fig. 6 is a cross sectional view of a set of finishing dies and the mandrel employed therewith as designed for the manufacture of the core whose cross section is shown in Fig. 2- Fig. 7 is a front view of a reliner or flangeless core; Figs. 8 and 9 are sectional views of two different constructionsof such cores; Fig. 10 is a plan view of an inner tube mandrel embodyin our improvement; Fig. 11 is a sectiona view of the mandrel shown in Fig. 10; and Fig. 12 is a cross sectional view of the dies used for compressin to its finished stage the section shown in g. 11.

The devices shown in Figs. 1-6 are con-' structed essentially in accordance with the process set forth and claimed in our 00 nd ing application filed June 26, 1918, erial No. 242,019, the same bein a division of our earlier application filed %)ctober 22, 1917, Serial No. 197,785; that is to say: suitable pieces of sheet metal are first formed by stamging between dies to the appropriate chan' Zll-shape, then welded together to form arcuate hollow bodies, a suitable mandrel is inserted as shown at a in Fig. 6, and the bodies forced to the requisite shape and size by striking between finishing dies BB as shown in Fig. 6, Whereby the metal of the entire core is forcibly stretched to its completed shape under this single blow, and the various strains due to welding and other operations are overcome. According to our present invention, the edges of the blanks which form the eripheral portion of the section, instead 0? being sheared flush and smooth are bent inwardly to form a continuous internal flange 1-1. This produces the double advantage of providing a stiffening web at that point and also, by rounding the outer edge of the bend as at 22, to produce a shallow groove for the reception of the weld material 3 and thus avoids the ne' cessity of ehamfering or beveling the edges. ed to the stiffness pro- This weld metal, a'd duced by the flanges 1-1 produces a kind of peripheral bridge which is extremely efiica cious in preventing denting or distortion one of many diflerent points. In Fig. 2 these p are shown at 55, as located along the flat sides of the core and somewhat removed from the internal rim, the core being completed .by additional channel-pieces or blanks 6 which similarly have intnrned flanges 7 which match the flanges 5 and by as described in our patent granted J u y the bending produce a groove for the weld material at 8. In the embodiment shown in Fig. 3 the side seams are formed at the rolmded side of the.core', 90 from the first seam, but are formed in the same manner, namely by the intnrned flange 5 abutting against the flange 7 of a blank section 6* and joined by a weld 8*. This arrangement has the added advantage of giving great stifiness against dents by sidewise blows.

The modification shown in Fig. 4: comprises only two blanks and one Weld, the free edges of the blanks being clamped to afiller member or stiffening, rin 10, by means of the securing ring or clam 11,

1918, No. 1,273,032. In the modification illustrated in Fig. 5, the rim is made of' a separate member 12 rolled to channel form, and the body of the mandrel is secured thereto by longitudinal welds 13-13, one at each side. In this embodiment the core is brought to finished form by the compression method described and claimedin our copending application filed January 22, 1919, Serial No. 272,412.

The reliner mandrels shown in Figs. 7,

8, and 9 are formed arbund their outer peripheries with the same intnrned flanges 1-1 formin a peripheral stiffening bridge and also de ning a space for the weld metal 3. The remainder of the article can be made in anydesired way, for example'by welding the two side-members directly together at 15, as shown in Fig. 8, or by inserting a channel as shown at 16, in Fig. 9, and welding the same at two places 1717; or in numerous other modes not illustrated.

Likewise the tube mandrels shown in Figs. 10 and 11 which are exactly circul. r in section have the same identical peripheral bridge formed by the intnrned flanges 1-1 and weld metal 3. All the last devices are preferably fashioned according to the process setforth in our application No. 272,412, last above mentioned, namely by compression in finishing dies 0 c as shown in Fig. 12 operating upon the last named tube mandrel. The tube mandrel shown in Fig. 10 is discontinuous while the remaining mandrels are continuous owing to the fact that casings and liners, while continuous, are

'split all the way around and can hence be removed from a circular complete mandrel, while inner tubes are made of a complete tubular form but not endless which necessitates a discontinuous mandrel to permit their removal.

It will be understood that the generic "idea of our invention can be realized by many means and constructions not herein specifically set forth, wherefore we do not restrict ourselves to our exact disclosure except as pointed out in the claims hereto annexed.

Having thus described our invention what we claim is 1. A tire forming mandrel having a body part made of sheet metal in approximately torus form, said body part being formed at its portion of greatest diameter with an integral intnrned stiffening rib.

2. A tire forming mandrel having a hollow curvilinear body part made of sheet metal and formed with a longitudinal internal, peripheral stiffening rib.

3. A tire forming mandrel comprising a hollow arcuate sheet metal body having at its portion of greatest diameter an intnrned integral stifiening flange.

' 4. A tire forming mandrel comprising a plurality of arcuate sheet ,metal channel members having intnrned margins, said channel members being assembled together to form a hollow body and welded together along their meeting edges, whereby said intnrned margins will form reinforcing ribs. 5. A tire forming mandrel comprising a hollow arcuate sheet metal body having at its portion of greatest diameter an internal, rigid, circumferential reinforcement.

' 6. A tire forming mandrel comprising a plurality of arcuate sheet metal channel members located with their marginfs in contact and welded together, said margins being turned inwardly for the double purpose of producing increased stiffness and producing a groove for the weld-metaL 7. A tire forming mandrel comprising a plurality of arcuate sheet metal channel members each having its margin turned inwardly to produce a. flange and welded to the margin of the adjacent member. 10 In testimony whereof, we hereunto afiix our signatures.

' DON A. CLARK.

CLYDE E. LOWE. 

